Selection Guide
Solar Pump Selection Guide: Inverter, Controller or VFD?
When we select a drive for a water pump, we do not start by asking whether the customer wants an inverter, controller or VFD. We first read the pump motor.
Voltage, phase, current, water duty and installation environment decide the answer. The product name comes after that.
Inverter
AC pump drive
Controller
custom/protected
VFD
motor speed
Drive Choice
The practical difference: inverter, controller and VFD
These terms overlap in the market. We separate them by what the device must do for the pump.
Solar pump inverter
Best for standard AC pump motors. It converts PV or AC input into controlled motor output and keeps the pump running under changing sunlight.
- SP1 for 220V single phase
- SP2 for phase conversion
- SP3 for 220V three phase
- SP4 for 380V three phase
Solar pump controller
Best when the project needs controller-led matching, custom voltage, protected outdoor use or OEM configuration.
- SP5 for customized PV pump controller work
- SP6 for protected submersible controller projects
- Cabinet integration when wiring and protection matter
Solar pump VFD
Use VFD language when the customer is asking about AC motor speed control. In SolarSeeker products, the solar pump inverter is the VFD-style path with MPPT and pump protection.
- Confirm pump voltage and phase
- Check rated current and cable distance
- Use SP4 for most 380V VFD pump work
Selection Table
Use pump data to choose the product path
This is the table we use before quoting. It keeps broad requests such as solar water pump or VFD for water pump tied to the real motor data.
| What the customer has | What we check | Recommended path | Open |
|---|---|---|---|
| 220V single-phase pump | Pump current, head and small farm or well duty | SP1 220V single phase solar pump inverter | SP1 |
| Single-phase site, three-phase pump | Whether the pump should be kept instead of replaced | SP2 single phase to three phase solar pump inverter | SP2 |
| 220V three-phase pump | Commercial pump load and 220V three-phase output | SP3 220V three phase solar pump inverter | SP3 |
| 380V three-phase pump | Deep well, large irrigation, high-power or industrial duty | SP4 380V three phase solar pump inverter | SP4 |
| Existing pump system needs custom control | Voltage, phase, input/output and OEM label needs | SP5 customized PV pump controller | SP5 |
| Outdoor submersible controller project | Sand, dust, salt fog, water source and protection level | SP6 protected submersible pump controller | SP6 |
Our Rule
If the nameplate is missing, we treat the selection as provisional
A customer can describe the pump as a solar well pump, AC pump, submersible pump or VFD pump. That language helps, but it does not replace the motor label.
Do not choose by HP alone
Rated current and voltage decide whether the drive is actually safe.
Do not use charge-controller logic
A pump controller drives a motor. A battery charge controller is a different product.
Do not ignore the site
Desert, coastal and remote sites may need cabinet protection and simpler fault diagnosis.
Product Links
Go from selection to the product page
Once the path is clear, use the product pages for model details, images, tables and inquiry.
Main Catalog
Solar Pump Inverters
Use this page as the main product route for SP1-SP4 and related systems.
High Power
380V / SP4 Path
For deep wells, large irrigation and three-phase pump motors.
Controllers
SP5 / SP6
For PV pump controller and protected submersible controller work.
Package
Kits & Accessories
For matched pump, drive, panels, sensors and field accessories.
FAQ
Solar pump selection FAQ
Answers we normally give before quoting a pump drive.
Is a solar pump inverter the same as a solar pump VFD?
In many customer conversations, yes. A solar pump inverter is the solar-ready VFD path for AC water pumps: it drives the motor, tracks PV power and protects the pump. We still confirm voltage, phase and current before selecting a model.
When do we choose a controller instead of an inverter?
We choose a controller path when the project needs customized input/output, OEM configuration, submersible pump protection or a protected controller package. For standard AC motor drive, the inverter path is usually clearer.
Can one page cover inverter, controller and VFD selection without cannibalization?
Yes, because this guide is a decision tool. The product pages still own the product keywords and model details; this guide simply sends the customer to the right product path.
What is the minimum data needed for selection?
A pump nameplate photo, head, flow, cable distance, water source type, PV panel plan if available and project country are enough for the first recommendation.
Where should a customer go after this selection step?
If the drive path is clear, go back to the Solar Pump Inverters catalog or the specific SP model page. If the whole package is unclear, move to the system design guide.
Engineer Check
Send the nameplate before selecting the drive
If the pump data is clear, SolarSeeker can quickly tell you whether the project needs SP1, SP2, SP3, SP4, SP5, SP6 or a complete package.
Get Selection Help